Historically, it has been extremely difficult to achieve both high strength and good toughness in steel welds with yield strengths (YS) above 100 ksi in matching strength alloys, such as HSLA-100/115 and HY-100/130. High strength is attainable, but often not in conjunction with consistently good toughness over a range of welding conditions, cooling rates, and service temperatures. Generally, high strength steel welding consumables produce weld deposits that exhibit an inverse relationship between YS and impact toughness, and tend to be sensitive to cooling rate. For example, MIL-1205 and MIL-140S solid wire consumables produce welds that display the inverse relationship between YS and impact toughness.
High nickel steel welding consumables, generally defined as steel consumables having between 3-12 wt. % Ni, have been investigated by researchers since the 1960s as a way to achieve both high strength (>100 ksi YS) and good toughness. While the previous work in this area has been promising, a robust, commercially available, high strength, good toughness welding consumable still does not exist in today's market that meets many commercial and military application requirements.
Consequently, there is a need for a matching strength solid wire welding consumable for high strength steels (YS of 100 ksi and greater) that produces a weld deposit with stable mechanical property performance when used in a variety of welding conditions which produce good toughness across a range of cooling rates, and when exposed to low service temperatures.